Simplify the expression. $ (7x^{4}+4x) + (-x^{7}-7x ) + (-x^{7}-4x^{5} ) $
Explanation: Since we are adding polynomials, we can simply remove the parentheses. $7x^{4}+4x - x^{7}-7x - x^{7}-4x^{5}$ Identify like terms. $ + {7 x^4} + \color{#9D38BD}{4 x} - { x^7} - \color{#9D38BD}{7 x} - { x^7} - \color{#DF0030}{4 x^5} $ Combine like terms. $ { ( -1 -1 ) x^7} + \color{#DF0030}{ -4 x^5} + { 7 x^4} + \color{#9D38BD}{ x} $ Add the coefficients. $-2x^{7}-4x^{5}+7x^{4}-3x$